My response to the article is that you’re sacrificing gains in language because some people use outdated tools. Code has more context than what is just written. Many times you can’t see things in the code unless you dig in, for example responses from a database or key value store, or literally any external api. Type inference in languages that have bad IDE support leads to a bad experience, hence the author’s views on ocaml. But in a language like Kotlin it’s absolutely wonderful. If needed you can provide context, but otherwise the types are always there, you can view them easily if you’re using a decent IDE, and type inference makes the code much more readable in the long run. I would say that a majority of the time, you do not care about the types in any application. You care about the data flow, so having a type system that protects you from mismatched types is much more important that requiring types to be specified.